In recent years, an information display device, such as a personal computer (PC) or the like, displays respective kinds of information in independent screen elements each referred to as a window in order to display various kinds of information on a single display screen.
For example, many web browsers or the like which produce information to be displayed (display target information) based on web page data obtained via a network from a web server or the like and display the display target information produced based on the respective web pages, each in each window.
Such an information display device for displaying information in a plurality of windows may need to show notice information asking for user confirmation of their operation or input of a password or the like in connection with display target information shown in any window.
As a specific example, in the case of a web page, HTML (Hyper Text Markup Language) data describing a web page may contain a description about a program to be processed (a script) for controlling such that display of display target information is not carried out until a password is input.